doc, QQuickTreeView: hasChildren should be bool, not int

This patch corrects the type in the documentation.

Pick-to: 6.5 6.4
Change-Id: I9a3114fb3a1b2f72efc73ec471d6c49cafe08701
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

src/quick/items/qquicktreeview.cpp

@@ -68,7 +68,7 @@
         \li \c {required property bool expanded}
                 - Is \c true if the model item drawn by the delegate is expanded
                 in the view.
-        \li \c {required property int hasChildren}
+        \li \c {required property bool hasChildren}
                 - Is \c true if the model item drawn by the delegate has children
                 in the model.
         \li \c {required property int depth}